This document relates to devices and techniques for locking and tuning the frequency of a tunable laser.
In various laser applications, it is desirable to stabilize the laser frequency at a given frequency. Such applications include, for example, spectroscopic measurements and other devices based on stabilized lasers such as photonic tunable microwave filters, optical sensors (e.g., fiber Bragg grating sensor interrogation) and generation of microwave signals based on opto-electronic oscillators or mixing laser light form two lasers. A laser, however, tends to fluctuate in frequency due to external perturbations, thermal variations and other factors. Some commercial tunable lasers, for example, can drift or fluctuate in frequency on the order of tens of MHz in the free running condition. To meet frequency stability requirements in various applications, a laser can be stabilized in frequency by locking the laser to a frequency reference.